The number of people diagnosed with cancer world wide has significantly increased and continues to rise at an alarming rate. Cancer is characterized by an increase in the number of abnormal cells derived from a given normal tissue, invasion of adjacent tissues by these abnormal cells, or lymphatic or blood-borne spread of malignant cells to regional lymph nodes and to distant sites (i.e., metastasis).
Of special interest are individuals diagnosed with androgen-dependent disorders, such as prostate cancer, and estrogen-dependent disorders, such as breast, uterine, and ovarian cancer.
Prostate cancer is currently the most common non-skin cancer and the second leading cause of cancer-related death in men after lung cancer. The primary course of treatment for patients diagnosed with organ-confined prostate cancer is usually prostatectomy or radiotherapy. These treatments for prostate and breast cancer are highly invasive and characterized by undesirable and serious side effects. Furthermore, a large percent of individuals who receive localized treatments such as surgery or radiotherapy may suffer from recurring cancer and widespread metastases. As with surgery and radiation therapies, there are several drawbacks to chemotherapy, including the fact that almost all chemotherapeutic agents are toxic, and chemotherapy causes significant, and often dangerous, side effects, such as severe nausea, bone marrow depression, and immunosuppression. Additionally, many tumor cells are resistant or become resistant to chemotherapeutic agents through multi-drug resistance.
Treatments such as hormone therapy are another option for individuals diagnosed with hormone-dependent, hormone-responsive, or hormone-sensitive cancers, such as prostate or breast cancer. However, some individuals who have been administered current hormone therapy treatments may not show a significant response to such treatments and some may suffer from relapsing of cancer.
Currently chemo-refractory and hormone-refractory cancer patients are left with very few treatment options and there remains an unmet need for more effective ways to treat cancer such as, but not limited to, prostate cancer and breast cancer.
The demonstration by Huggins and Hodges C. V., (Cancer Res., 1941, 1, 293) and Huggins et al in Arch. Surg., 1941, 43, 209 lead to androgen ablation being considered as a possible approach to treatment. It has been demonstrated that testosterone levels are reduced by orchidectomy or by administration of GnRH analogs (gonadotropic releasing hormones). GnRH analogs can have side effects such as cardiovascular degeneration and osteoporosis, which are the two most potentially serious conditions induced by the continuous presence of GnRH. Moreover these treatment options only eliminate testosterone production from the testes and not that produced by the adrenal.
In the adrenal glands, the biosynthetic cascade also leads to the formation of gluco- and mineralcorticoids.
Since androgen and estrogen are hormones having various physiological activities such as differentiation and proliferation of cells and the like, it was thought that potent and specific compounds that inhibit androgen synthesis in the testes, adrenals, and other tissue may be more effective for the treatment of PCa (Njar, V. C. O.; Brodie, A. M. H., “Inhibitors of 17α-hydroxylase-C17-20-lyase (CYP17): Potential agents for the treatment of prostate cancer”, Current Pharm. Design, 1999, 5: 163-180).
In order to avoid unwanted side effects, androgen biosynthesis inhibitors have to be specific enough not to influence corticosteroid biosynthesis. A promising novel strategy for the treatment of prostrate cancer is the development of strong and selective inhibitors of CYP 17 as this would result in complete and exclusive elimination of androgen biosynthesis as suggested in Current Medicinal Chemistry, 2005, 12, 1623-1629.
Steroid-type compounds and non-steroid-type compounds are already known as steroid C17-20-lyase inhibitors. The steroid-type compounds are disclosed in, for example, WO 92/15404, WO 93/20097, EP-A 288053, EP-A 413270 and the like. As non-steroid-type compounds, for example, in WO94/27989, WO96/14090 and WO97/00257 azole derivatives are described in WO95/09157 1H-benzimidazole derivatives are described in U.S. Pat. No. 5,491,161, dihydronaphthalene derivatives are described in WO99/18075, and naphthalene derivatives are shown in WO99/54309.
A variety of potent steroidal and non-steroidal inhibitors of CYP 17 have been reported and some have been shown to be potent inhibitors of testosterone production in rodent models (Njar and Brodie, above). Jarman and colleagues have described the hormonal impact of their most potent CYP 17 inhibitor, abiraterone in patients with prostate cancer (O'Donnell et al., “Hormonal impact of the 17α-hydroxylase/C17,20-lyase inhibitors abiraterone acetate (CB7630) in patients with prostate cancer”, Br. J. Cancer, 2004, 90: 2317-2325). Abiraterone has been discussed in patents such as WO 200900132, WO 2008024485, WO 2006021776, WO 09509178, WO 09320097
Non-steroidal small molecule inhibitors have been described for example in BMC 2004, 12, (4313), YM 116, 2-(1H-imidazol-4-ylmethyl)-9H-carbazole, and their effects in decreasing adrenal androgen synthesis by inhibiting C17-20 lyase activity in NCI-H295 human adrenocortical carcinoma cells has been described by Ideyama Y, Kudoh M, Tanimoto K, Susaki Y, Nanya T, Nakahara T, Ishikawa H, Fujikura T, Akaza H, Shikama H in “Jpn. J. Pharmacol., 1999, 79: No. 2(213-20)”. Novel non-steroidal inhibitor of cytochrome P450 (17 alpha-hydroxylase/C17-20 lyase), YM 116, and its role in decreased prostatic weights by reducing the serum concentrations of testosterone and adrenal androgens in rats has been reported by Ideyama Y, Kudoh M, Tanimoto K, Susaki Y, Nanya T, Nakahara T, Ishikawa H, Yoden T, Okada M, Fujikura T, Shikama H Proc. Am. Assoc. Cancer Res., 1998, 39:89 Meet. (384)
Synthesis and biological evaluation of novel non-steroidal inhibitors of steroid 17,20 lyase has been described by -Yoden T, Okada M, Kawaminami E, Kinoyama I, Ideyama Y, Isomura Y in Abstr. Pap. Am. Chem. Soc., 1997, 213 Meet.: Pt. 2(MEDI206)
Further illustrative of the background of the invention are patent applications such as US20080280864A1 or WO28154382A1.